package com.itheima;

import com.itheima.Student;

import java.util.Comparator;
import java.util.TreeSet;

public class TreeSetDemo {
    public static void main(String[] args) {
        test3();

    }
    public static void test2() {
        //集合只能存储引用数据类型，不能存储基本数据类型
        TreeSet<Integer> set1 = new TreeSet<>();
        //1---》包装成Integer对象---》自动装箱
        set1.add(5);
        set1.add(4);
        set1.add(3);
        set1.add(2);
        set1.add(1);
        for (Integer integer : set1){
            System.out.println(integer);
        }
    }
    public static void test1() {
        TreeSet<Student> set = new TreeSet<>();
        set.add(new Student("王五", 20));
        set.add(new Student("张三", 18));
        set.add(new Student("李四", 19));
        set.add(new Student("赵六", 21));

        for (Student s : set) {
            System.out.println(s.getName() + "---" + s.getAge());
        }
    }
    public static void test3() {
//        Comparator<Student> comparator = new Comparator<Student>() {
//            @Override
//            public int compare(Student o1, Student o2) {
//                return o1.getAge() - o2.getAge();
//            }
//        };

        Comparator<Student> comparator = (o1, o2) -> o1.getAge() - o2.getAge();
            //如果时正序，o1-o2
            //如果时倒序，o2-o1

        TreeSet<Student> set = new TreeSet<>();
        set.add(new Student("王五", 20));
        set.add(new Student("张三", 18));
        set.add(new Student("李四", 19));
        set.add(new Student("赵六", 21));
        for (Student student : set) {
            System.out.println(student.getName() + "---" + student.getAge());
        }
    }
    //可变参数必须时形参的最后一个
    public static int sum(String name,int... a) {
        int total = 0;
        for (int i = 0; i < a.length; i++) {
            total  += a[i];
        }
        return total;
    }


}
